Security firms link Democratic Party hack to Russians

Two U.S. cyber-security firms say that their analysis of computer breaches at the Democratic Party's funding group for congressional candidates shows detailed evidence that the intrusions were likely linked to Russian hackers.

FBI investigates possible hack on Clinton campaign

The two U.S. companies said in separate posts today that internet domains and registrants used in the breach of computers used by the Democratic Congressional Campaign Committee, or DCCC, tie back to a Russian hacking group linked to that nation's intelligence services. That same hacking group, known as "Fancy Bear," was previously connected to the June cyber breach at the Democratic National Committee.

Both firms, Fidelis Cybersecurity and ThreatConnect, said the hackers created a fake internet DCCC donation site. The registrant for the fake DCCC site was linked back to other web domains used by "Fancy Bear."

A U.S. intelligence official told CBS News last week that the signature of the DCCC breach is Russian and the U.S. government has identified methods and techniques used by Russia in past hacks that mirror those used in the DNC incursion. Another U.S. official told CBS News that the Obama administration believes Russian state actors are behind the leak, confirming the hackers "left all kinds of fingerprints."

Hillary Clinton campaign officials have suggested that Russia breached the network at the DNC in order to influence the U.S. presidential election in favor of Donald Trump. While President Obama declined to speculate on the motivations, he told NBC News that "anything's possible."